KZ Carol Pro - True Wireless BT Earphones
$40 at Amazon: https://amzn.to/3Q1xWiN
Hardware Overview
For a pair of budget earphones, I really like the look of the black Carol Pro earphones. The stem bodies are transparent and have little LEDs in them that indicate when they’re connected or in pairing mode. They remind me of earphones from Nothing. The bodies of the earphones are a glossy black and the provided oval-shaped ear tips are matte black silicone. The medium-sized tips are pre-installed and two additional sets are provided in the box. I found that the medium tips worked fine for me.
The charging case reminds me a lot of the cases from QCY and SoundPeats. These companies probably all use the same original equipment makers but with some minor tweaks to design here and there to make them a bit more distinguishable. This particular case is especially generic. The main differentiating feature on the case is the large thin strip of LED lighting that lets you know how much charge remains in the case. It’s a larger LED than what I’ve seen on any other earphones in my collection. The charging case has a USB-C port on the bottom, and it can stand upright on a flat surface. The back of the case is smooth with no branding at all. The case does not support wireless charging.
Software Overview
There is no accompanying app for the Carol Pro. You may consider this a pro or a con, depending on your experiences with apps for Bluetooth audio devices. There are four modes for the Carol Pro, and you access them with touch controls. This is the closest thing you get to EQ settings.
Bluetooth Connection
The Carol Pro support Bluetooth 5.4, which is not the latest version, but it is a version that supports most of the latest Bluetooth features. Nevertheless, the Carol Pro aren’t fancy in terms of their Bluetooth features. These aren’t Hi-Res Audio certified. But they do support LDAC, AAC and SBC, with LDAC providing the highest bitrate for the best audio experience on devices that support it. KZ says that latency with the Carol Pro is 55ms. That’s not the best, but it’s decent enough for some gaming. Bluetooth range with the Carol Pro is about average. I didn’t experience any dropouts while wandering around my house or outside to get my mail.
Noise Canceling/Transparency
The Carol Pro have 6 microphones that are used for active noise cancellation as well as voice pickup for calls and voice assistant prompts. The ANC here is called hybrid ANC and KZ says it uses “super-linear high-sensitivity in-magnet drivers” to overcome the issue of properly emitting sound waves to cancel out noise in the environment. The driver type is not specified, but based on the product photos, dynamic drivers are used. I don’t think that the ANC technology here is much different than the ANC in other similarly priced Bluetooth earphones. Anything new and special would dictate new and special pricing. Despite KZ’s claims that the ANC can reduce noise by as much as 55 decibels, the ANC here is below average. It will reduce the sounds of low rumblings like air conditioners or white noise like air purifiers a bit, but it won’t eliminate voices or higher-pitched noises. You will still be able to hear the clicking of your keyboard just fine. I wouldn’t buy these for their ANC performance. The transparency mode lets in more noise as you’d expect, but sounds a little louder than reality with a bit more white noise than what you hear with the earphones removed. It’s not a natural sound, but if the goal is just to hear your surroundings better, it achieves that goal. It also has the effect of making the ANC setting seem more effective as you cycle through the modes.
Battery Life
The KZ product description indicates that the battery is lithium cobalt oxide. It turns out that there are different types of lithium-ion batteries and cobalt oxide is one that is designed to be more energy dense for demanding applications like phones, tablets, and computers. There are also lithium iron phosphate and lithium nickel manganese batteries that have different purposes. Iron phosphate is designed for safety and is more often used in cars and solar energy storage. Nickel manganese batteries strike a balance between the two and are often used in power tools and e-bikes. So lithium cobalt oxide isn’t particularly special, but KZ wants you to know they picked the one that ostensibly offers the best battery life.
KZ states that the earphones and case can provide 35 hours of listening time. Most likely, this is without ANC and LDAC enabled as those features will drain the batteries faster. On KZ’s website, they list the earphone battery life as up to 7 hours with a 10-minute charge providing 2 hours of listening time. This means the case can recharge the earphones up to 5 times. The earphones have 40mAh batteries and the battery in the case is 300mAh. The case charges via USB-C but does not support wireless charging.
Microphone Performance
The Carol Pro have above average microphone performance in quiet conditions. With a bit of wind the performance dips precipitously, as with many other more expensive earphones. Voice comes across clear and loud when there's no background noise, however, so these could be a solid choice for calls in a quiet place. Voices sound less compressed than they do on the Soundcore P40i and come across clearer and louder than on the SoundPeats C30. The Carol Pro and Soundcore do a better job of suppressing background noise over the Space Travel 2 and C30. For indoor use, the Carol Pro arguably have the best microphone performance in this grouping.
Sound
I compared the Carol Pro against the similarly priced Moondrop Space Travel 2, the SoundPeats C30, and Soundcore P40i. With their out-of-the-box sound, the Carol Pro has decent fullness in the low end and midrange. There are enough highs to sound pleasant without being too bright or sibilant. There is nice detail in high-pitched sounds like cymbals and high-hat hits. The Space Travel 2 sounds a bit flatter as there is less low-end presence, but the midrange is well represented. However, the Space Travel 2 can be tweaked with EQ settings that are among the best available in the industry. The SoundPeats C30 are brighter than the Carol Pro and also have less presence in the low end. The sound from the C30 feels more constrained and congested than the Carol Pro. The Soundcore P40i have a bit more bass but an ever-so-slightly tinnier sound overall than the Carol Pro, but as with the Space Travel 2, you can do quite a bit of sound tweaking in the app. If you are not interested in tweaking or do not want to install apps to control sound, the Carol Pro will sound better by default to most people. They aren't at all bass monsters; the overall presentation is well-balanced. The clarity of both earphones is very similar. Their performance with ANC turned on is also about the same as both have fairly weak ANC.
Conclusion
For less than $40, the Carol Pro are a solid option as long as you're not a person who wants to tweak the sound. The default tuning is pleasant with decent enough detail to enjoy your music and there's a bit of ANC to help take the edge off environmental noise. The microphones perform very well in quiet environments and the earphones themselves look good with their Nothing vibe. They're a good pair of budget earphones for everyday listening or just as a backup pair you can toss in your bag and use on the go as needed.
